New Bathroom Mixer Taps are creating a Water Hammer Issue

[Libby Stano]

We are renovating our upstairs bathrooms and there is an issue with shutting off the new mixer fittings - all six of them.

The matter is holding up progress though it seems no one knows what to do.

We built our home about 28 years ago. The only mixer we installed was in the kitchen, all the bathrooms had taps.

I have gone for wall mounted mixers for the renovation.

Flick the mixer off and there is a bang. To my untrained ear it sounds like it is coming from the cartridge.

My plumber was adamant it was not his pipe work.

The manufacturer sent out a plumber who changed one of the cartridges - no change.

He questions some of my plumber's pipe work.

We are in a high pressure area so my plumber at the suggestion of the tap manufacturer installed a pressure regulator at the main valve.

The pressure was within the limits of the mixers warranty before the regulator's installation but it has made no difference.

We tried a different mixer brand I bought from Bunnings - no change.

My plumber is coming back with a Caroma mixer he wants to try.

My builder sent out a third plumber. We turned off all the valves in the house - no change.

He inspected the pipe work of my plumber. He said it was very neat and secure.

He went out to the mains valve while I turned the worst mixer on and off. He said he could feel the vibration at the meter.

Two years ago we renovated the kitchen. I had a second sink added. There was no problem with water hammer when this was added.

Three plumbers and we are no closer to a solution.

It seems the experts are stumped by this puzzle.

Does anyone out there have any suggestions?

I would be grateful for any ideas

 

[Knappers]

Is the reducing valve adjustable?
You could try water hammer arrestor/shock arrestor, usually near outlet but one near reducing valve may help too

 

[ShaunCorbs]

What happens if you close it slowly ?

 

[oz-plumber]

Hi Libby,

Do you have copper piping installed anywhere in the house?

What brand of mixer taps do you have installed?
What is their recommended water pressure to the tap?

Whats the pressure from the incoming mains?
Whats the pressure reduced down to after the reducing valve.

Mixer taps have always caused problems with the quick shut off of water.
Not so prevalent nowadays due to the use of plastic / composite piping in most homes.
The plastic expands to take the shock, hence no sound of water hammer.

When a mixer tap shuts off, or dishwasher / washing machine shuts off via a solenoid valve, the pressure increases @ 6 times for an instant, causing water hammer.

As for the manufacturer blaming the plumber or their plumbing for failure of their products - they all do.
It's easier to blame the plumber than admit their product is not fit for purpose.

 

[Libby Stano]

Thank you to those who replied
Firstly Sydney Water have been and changed the T section at the meter not the valve however

Secondly the new plastic pipe is definitely connected to older copper pipe

Thirdly I am now convinced it is the speed with which you flick the mixer on and off because I have played with it myself

There is a single bang when the mixer is flicked off quickly the amount of bang varies with the speed at which you turn it off from no bang at all to unacceptable

To turn it off with no bang at all I didn’t really think the speed was ridiculously slow and that eventually we would subconsciously learn to slow down the speed at which we turn the mixers off

The taps are made by Roger Seller - Winnings Appliances Model - Tonic

The plumber sent out by the above said the cartridges were German made

Fourthly the water pressure is within the capacity of the tapware

Our question is why doesn’t it happen downstairs in the kitchen

 

[Knappers]

It definitely seems to be water hammer.
The hammer is as much to do with the momentum of water in pipes as it is pressure.
The design of the cartridges will perhaps be adding to the issue but the volume of moving water will be much greater for upstairs taps and that is probably why it's not such an issue in the kitchen.
The shock arrestors that I've pointed out would likely help and its still my advice.
It may be worth looking at changing/fitting flow restrictors or aerators on the taps to limit the flow and as a result the speed of water through the pipes.

 

[Libby Stano]

It has been recommended today that we install stop valves in the ceiling for each separate bathroom

Can anyone tell me whether this is becoming a common problem when people update their tapware

The plumber working for the manufacturer has indicated it is not however it is sounding more and more like it is not that uncommon

My builder contacted the Master Plumbers Assoc and the man he spoke too requested that if we resolved the issue to let him know so he could tell his students what to do in the same situation

We are currently waiting on delivery of a Caroma slow closing mixer so we can get a comparison

Thanks again for the responses
Libby

 

[oz-plumber]

Who recommended putting stop taps in for each bathroom?

I can't see how that would achieve anything. It will just be another valve to close when you turn a tap off.

What sort of hot water service do you have - storage or instantaneous.

Try turning off the cold water inlet valve to the hot water service and then check the offending taps.
You will only be able to test the cold water - HWS off.

Have you got a pressure limiting valve installed at the water meter.
I have had a couple of times them starting water hammer on places that never had it before.
It probably easier to replace the Pressure limiting valve and see if that fixes the problem

 

[Libby Stano]

Sorry everyone, I have only had internet on my phone over the past 2 weeks, waiting for
Foxtel Broadband to connect us up. Using my phone to type is hopeless.

Ok the manufacturers plumber recommended stop valves in the ceiling. My husband is dead against it.

Last night he suggested we try isolating the problem. Disconnect the water to the bathroom where the hammer is
at its worst, then see if there is still a problem in the bathroom remaining connected. If there is no hammer then the problem is only in the disconnected room.

The hot water service is a Rheem. It's big so I guess we store hot water.

A pressure regulator was attached after we discovered we had the problem. It was installed at the suggestion of
the tap manufacturer.

I am not sure which valve to the hot water you are talking about.

I am guessing the one going to the pilot light is gas.

There is a pipe that runs into the bottom of the tank but it also has a T intersection with a pipe running to the top of the
tank and connecting to another pipe coming out the top of the tank. The pipe is warm so the valve attached to that must be the hot, obviously.

If it is the valve on the pipe running into the bottom and that is the only valve left it must be the cold inlet valve.

When the third plumber came that was the first thing he did. Then we ran round downstairs shutting off the stop valves in the kitchen, laundry and guest bathroom as well.

It made no difference. Should I do it again, leaving the other rooms alone?

Shouldn't cartridges be interchangeable? and can't we buy slow stop ones at somewhere like Reece plumbing? The cartridge I have said before is German made but I now know it is 35mm.

The specs say it is recommended that in-line filters are installed to ensure a clean flow of water to the mixer. I don't think they have been installed.

A tiny note at the bottom of the page says do not remove the cartridge as it has been factory pressure tested and tightened to an optimum torque?

The manufacturer's plumber when he came out changed the cartridge and I'm pretty sure he didn't use a torque wrench to screw it back together.

Max Hydrostatic Pressure - 1000kpa
Recommended Max H Pressure - 500kpa
Min Pressure - 150kpa

For optimum performance hot and cold inlet water pressure should be equal - I don't know if my plumber has checked this.

Thank you for replying.

Libby

 

[oz-plumber]

Hi Libby,

Sounds like you have a plumber that's on the ball - 3rd plumber.

Inline filters should not be required to taps installed.
I doubt debris in water supply is the issue.
Debris would only cause the taps to leak, not water hammer

I'm with your husband re: Stop taps. Will not do anything.
Manufacturers get out of jail card.

Is it predominately on the cold water or hot water the water water hammering is evident?

I assume the plumber for the renovation used plastic pipe for hot & cold water, so nothing has changed on the original copper piping, except the additional plastic pipe plumbing
If you didn't have the problem before, I doubt issues are caused by his work.

As for the cartridges, replace them with another brand, you will have no warranty on the taps.
Even Caroma have been adamant about this with replacing their cartridges with generic cartridges.

 

[Libby Stano]

Hi

I don't know if the hammer has a predominant side, hot or cold.

My plumber is coming in the morning with a slow stop Caroma tap. I think primarily to prove to everyone it is not his pipework.

He has nothing to prove to my husband and I, we agree it is the speed with which the mixer is turned off that is the issue.

I will ask him if the hammer has a predominant side.

I am going to try and attach a video, but when I tried putting it on Houzz Australia I lost my entire post. Better luck this time.

Will keep everyone following informed as to our Caroma trial.

Thank you for reading

Libby

 

[Loganliam]

Please check the problematic faucets after shutting off the hot water service's cold water inflow valve.
Only cold water will be available for you to test. Thanks